Published in the Proceedings of the National Academy of Sciences, the study looked at the impact of carbon emissions on coastal cities and calculated when it would be too late to save those cities by cutting emissions. (Video via NASA)

These coastal doomsday projections are nothing new. There have been many sea level studies, and scientists generally project the sea level will rise 4 to 6 meters by the year 2100. (Video via NASA)

But this study stresses "lock in dates" for each city, a kind of climate deadline were, if emissions aren't drastically cut back by a certain year, at least part of that city is going underwater. (Video via NASA)

Miami and New Orleans have already passed their lock in dates. Meanwhile, New York has until 2095 and Sacramento has until 2050. (Video via The National)

But apparently there's hope for some cities. Researchers believe that extreme cuts to carbon emissions and a shift to using more renewable energy could stop the trend. (Video via CNN)

The lead author of the study told CBS: "We are not talking about a sea level rise happening tomorrow. Instead, we are talking about what could happen if the genie we let out of the bottle continues to grow. We are talking about what could happen if we continue to emit this much carbon into the atmosphere."

But these dates shouldn't be taken as set in stone, because there are so many factors at play, no two doomsday studies are alike. For instance, a recent NASA study concluded it's already too late to stave off sea level rise, while the U.N.'s climate panel says that tipping point is years away.